Electric system



Oct. 16, 1951 R. H. RINES 2,571,163

ELECTRIC SYSTEM Original Filed Feb. 18, 1946 2 Sheets-Sheet 1 I12 VEIZi'OII 205527 b. ZINE-5 R. H. RINES ELECTRIC SYSTEM Oct-16, 1951 Original Filed Feb. 18, 1946 2 Sheets-Sheet 2 PULVSE Athzrngy .Dzventor: 205527 h! 2/4 55 M 2,

Patented Oct. 16, 19 51 ELECTRIC SYSTEM Robert H. Rines, Cambridge, Mass.

7 Originalapplication February 18, 1946, Serial No.- 648,482. Divided and this application May 5, 1948, Serial No. 25,244

32 Claims.

The present invention relates to electric systems, and more particularly to radio-receiving systems that, while having more general fields of usefulness, are especially adapted for use in television. The present application is filed in response to a requirement for division in application Serial No. 648,482, filed February 18, 1946.

An object of the invention is to provide a new and improved electronically-controlled radio-receiving system.

Another object is to provide a new and improved radio-receiving mosaic.

A further object is to provide a novel cathoderay tube circuit and mosaic for receiving radio waves.

Other and further objects will be explained hereinafter and will be more particularly pointed out in the appended claims.

The invention will now be more fully explained in connection with the accompanying drawings, in which Fig. 1 is a diagrammatic view of circuits and apparatus arranged and constructed in accordance with a preferred embodiment thereof; Fig. 2 is a view of a modification; Fig. 3 is a diagram showing an airplane object from which radio Waves are reflected and scattered to the receiving system of Fig. 1; and Fig. 4 is a view of a further modification.

An electromagnetic wave generator 4 is shown exciting a dipole 2 to produce ultra-high-frequency pulsed-radio'energy, say,- of 3 or 1.5 centimeters wavelength. A continuous-wave or any other type of modulated-wave generator may be employed, but pulsed energy, at present, has the advantage of economical and easy high-power ultra-high-frequency generation.

The waves emitted by the dipole 2 may be directed by a reflector 3 upon a parabolic refiector 6. The parabolic reflector 6 is shown directing the wave toward an object, say, an airplane 8, from which they are reflected and scattered toward a receiving station.

At the receiving station, the radio waves thus reflected and scattered from the object 8 may be focused by an electromagnetic dielectric lens 5, such as polystyrene, upon a bank or array I comprising a plurality of normally ineffective radioreceiving pick-up unit antenna elements. The dielectric lens may be replaced by any other type of well-known lens, mirror or other directive system for focusing the electromagnetic energy scattered and reflected from the object 8 on the bank or array I of pick-up elements.

The pick-up elements of the bank or array I areshown arranged in the form of rows and columns, in the proximity of the focal plane of the lens 5. The first or uppermost row of the bank is illustrated as comprising the sections I0, I2, I4, l6, etc., shown as equally spaced horizontally. The second row from the top is shown comprising the sections I8, 20, 22, etc. The third or next-lower row is shown comprising the sections 24, 26, etc., and so on for the remaining rows of pick-up elements. Though only a small number of pick-up units is shown in each row, this is merely for illustrative purposes, in order not to confuse the disclosure. It will be understood that, in practice, a large number of pick-up units wil be employed in each row, say, 180.

The sections I0, I 8, 24, etc., are arranged in the first or right-hand column. The sections I2, 20, 26, etc., are disposed in the second column from the right. The sections I4, 22, etc., are disposed in the third column from the right, and so on. There may be as many columns as there are pick-up units in each row. Though each column is shown as comprising only a few pick-up units, this is again in order not to complicate the drawings.

The pick-up units will, of course, all receive the reflected or scattered radio waves through the lens 5 simultaneously. There will be focused on each pick-up unit a radio-frequency voltage corresponding to the scattering from a corresponding view of the object 8. The pick-up elements will thus receive different field strengths of radio vention, the Visible picture I23 is caused to appear upon the fluorescent viewing screen I06 of a radio-frequency energy received by the pick-up elements.

Provision is made for first rendering the norof the first row successively effective momentari ly in the display circuits; for then rendering the pick-up units I8, 20, 22, etc., of the second row successively effective momentarily; for then rendering the pick-up units 24, 26, etc., of the third row successively efiective momentarily; and so I The pick-up units are shown arranged in an insulating disc 9 at the screen end of the oscilloscope-like member 89, and the pick-up units may be constituted of electrets.

An electret is a permanently charged dielectric formed by filling the gap between two electrodes, say, with molten resin, carnauba wax, or beeswax, and subjecting the electrodes to high voltage. By allowing the wax to cool during the application of the high voltage, a solidified permanently charged electric dipole is produced, having permanent piezo-electric properties such that the dimensions thereof vary in response to voltages and the dimensional variation, in turn, produces further voltage variations. Investigations in this field are described, for example, by A. Gemant in the Philosophical Magazine, S. 7. vol. 20, No. 136. Suppl. November, 1935, pages 929 to 952.

As described by W. G. Cady in Piezoelectricity,

'McGraw-Hill, page 235, mixtures of the resin or carnauba wax with other dielectric substances have produced long-lasting electrets. presently be explained that if these dielectric bases are combined in the same manner with radio-absorbing-and-rectifying materials, such as silicon or uranium oxide, the electrets can be particularly well adapted to the purposes of the 1' present invention. One of the electrodes of the electret, further, may serve to enhance the response to radio energy if, it is, for example, tuned to the radio waves, if it is one-quarter of a wavelength long.

The pick-up units previously described may be such electrets. The first row of units is shown composed of charged dielectrics I0, I2, I4, I6, etc., provided with top electrodes H0, H2, H4, H6, etc., respectively, and a common strip 43. The second row of units similarly is shown comprised of charged dielectrics I8, 20, 22, etc., provided with top electrodes II 8, I20, I22, etc. and a common strip 5I connected to the strip 43. Similarly, the third row is shown composed of charged dielectrics 24, 26, etc., with top electrodes I 24, I26, etc., and a commonterminal strip 51 connected to the other common strips 43 and 5I. The strips 43, 5| and 51 are shown connected by a conductor I8 to a grounded impedance 58, in the input circuit of an amplifier I9.

The cathode-ray-oscilloscope-like member 89 is shown provided with a cathode 95, a controlgrid electrode 93 and an anode 9T. Electrons emitted from the cathode 95 will become enabled, in response to proper stimulation of the grid 93, to pass by the grid 93 to the anode 91 of the member 89. The electrons will continue to travel in a stream from the anode 91, between a pair of vertically disposed deflector plates 99 and IN, of which the plate 99 is shown grounded, and between a pair of horizontally disposed deflector plates I03 and I05, of which the plate I05 is shown grounded, to impinge finally on the disc 9 of the member 89. A horizontal-sweep-time base, applied, as hereinafter more fully explained, to the vertically disposed deflector plates 99 and I0 I, will cause the electron stream from the cathode 95 to become deflected horizontally, and a vertical sweep-time base, applied to the horizontally It will 1 disposed deflector plates I03 and I05, will cause the electron stream to become deflected vertically. The rows of electret pick-up units may be positioned along the successive paths of the electron stream to enable the stream to impinge on them as it successively sweeps out the successive rows of the array I.

If, accordingly, the lens 5 is causedto focus the radio-energy picture on the oscilloscope-like member 89, the bank of electrets will act to ab- .sorb the incident radio-frequency energy. The

absorbed radio-frequency energy will alter the initial permanent polarizing static charge or voltage with which the electrets become sensitized during their preparation. This alteration results from several factors, including heating or pyroelectricefifects, the negative temperature coefiito produce direct-current potential differences. 7

These potential differences are representative of the radio-frequency energy impressed on the top tuned electrodes of the electrets in the radioreceiving circuits comprising these tuned electrodes, the detecting electrets and the grounded conductor I8. The rectification is produced by the detecting dielectric disposed between the electret electrodes. The variation of potential and charge along the bank of electretsis'thus a measure of the radio-frequency energy impinged on the array by the lens 5.

The resistance of the silicon or uranium oxide, as well as of the wax of the electret, since their temperature coefiicients are negative, changes withthe intensity of the impinging radio-frequency energy. A resistance variation is thus produced along the bank of electrets that is representative of the radio-frequency energy re.- ceived by the respective electrets.

These three effects involving the change of the electret charge upon the absorption by the electrets of the radio-frequency energy, the production of the direct-current potentials as a result of the detectionor rectification in the abovementioned radio-receiving circuits, and the resistance changes render the electrets extremely sensitive. A radio-energy image of the object 8 becomes thus recorded .upon the array of electrets as charged, potential and resistance distribution.

The bank of electrets may be scanned accord- 7 ing to either of two principles or according to a combination of the same. One principle involves measuring the variation in the electric charge and potential of the'bank at the moment that the electron stream impinges upon the successively Silicon and uranium-' result both as a consequence of'the absorption and of the rectifying action by the electrets of the radio-frequency energy received by the electret electrodes. As the electron stream successively impinges upon the successively disposed electrets, during the scanning, it successively discharges them. This produces a corresponding change in the input voltage to the amplifier I9, indicative of the radio-frequency energy impinged on the respective electrodes.

Th electron stream will instantaneously discharge each difierently-charged and differentlypotentialed electret to give an indication in the load 58 and the amplifier I9, or it will give rise to a change in the electron-beam current when it impinges upon the variously resistive electret elements, or there may be a combination of these efiects.

The scanning of the electrets may obviously also operate on the principle of change in electron-beam current transmitted to the load 58 upon impinging on surfaces of various resistances. As the stream hits these electrets of difierent resistances, a change in beam current occurs, which manifests itself in the input circuit ofthe amplifier I9. Mosaics of electrets for the member 89 may also tak the form of Fig. 2, where electrets 8I, 84, 86, 88 are provided with front electrodes I8I, I84, I86, I 88 exposed to the radio ener y converged by the lens The electrode strips IBI, I84, I86, I88 may be of length one-quarter of the wave-length of the radio waves and may be in the interior of the tube 89, facing the electron stream, and may be scanned by it. The electrodes 28I, 284, 286, 288 will be capacitively coupled to'the' front electrodes and will assumethe homocharge of the electret. Thus, the electron stream will impinge on surfaces of difierent charge or potential, and the scanning will take place accordin to the principles previously described.

The electrets may be separated from adjacent electrets by dielectric material 200.

.As the electron stream produced from the cathode 95, in response to appropriate horizontal-sweep-time-base voltages applied to the vertically disposed deflector plates 99 and IOI of the cathode-ray-tube-like member 89, travels across the pick-up elements in the disc 9, they will successively discharge into a grounded preferably linear amplifier I9, by :way of a conductor I8.

If desired, the amplifier I9 may be replaced by the same pulse generator 4, may be employed to trigger a horizontal-time-base-sweep circuit 63 and avertical-sweep circuit 69, according to conventional and well-known television technique. The pulse generator 6 may feed, through an at- .tenuator and rectifier I, to an oscillator or any similar or equivalent television circuit. One such circuit is shown as a pulse-recurrence-frequency multiplier 65, for applying many pulses corresponding to each radio-frequency pulse for the period between successive radio-pulses, to trigger the horizontal-sweep circuit 63. The horizontal- .time-base sweep will thereby be produced between the vertically disposed deflector plates 99 and IN, occurring as many times, say, between successive radioefrequerlcy' transmissions, as there are rows of pick-up antennas. The pulse generator 4 may also feed, through the attenuator and rectifier I, to trigger the verticalsweep circuit 69, once corresponding to every radio-frequency transmission. One vertical sweep will then occur between the horizontally disposed plates I03, I05 during the periods between successive radio pulse transmissions, corresponding to as many horizontal sweeps as there are rows of antennas, causing each of the horizontal sweeps to appear at successively lowerlevels on the oscilloscope-sweep face.

If the circuit 65 comprises an oscillator, the oscillations may be employed to trigger the horizontal sweep. The period of the oscillations which, as previously explained, is much less than the duration of each radio pulse, corresponds to the time of sweep across one row of the pick-up units in the disc 9.

If, as previously mentioned, continuous-wave radio transmission is employed, the verticalsweep circuit 69 may be triggered to produce one vertical sweep corresponding to as many horizontal sweeps from the horizontal-sweep circuit 63 as there are rows of pick-up units.

Means is provided for producing upon the screen I66 of the display oscilloscope 90, images corresponding to the radio-frequency energy received by the corresponding pick-up mosaic antenna elements. The screen I06 is illuminated by an electron stream in the oscilloscope 96. This electron stream is synchronized to travel with the electron stream of the cathode-ray -like member 89. The horizontal-sweep circuit 63 is connected to the horizontal-deflector plate I06 of the oscilloscope by a conductor 61, and to the horizontal-deflector plate IOI of the oscilloscope-like member 89 by the conductor 6! and a conductor I34. The vertical-sweep circuit 69 is connected to the vertical-deflector plate I02 of the oscilloscope 90 by a conductor II, and to the vertical-deflector plate I63 of the oscilloscope-like member '89 by the conductor 'II and a conductor I46.

The amplifier 19 is connected, by conductors;

8'5 and 81, to the control-grid electrode 92 and: the cathode 94 of the oscilloscope 90. The mosaic of electrets becomes thus successively connected, through the amplifier I9, to the control electrode: 92. Electrons emitted from the cathode 94 will& become enabled, in response to the action of the! amplifier 19, to pass by the grid 92, to the anode 96 of the oscilloscope tube 90. The electrons will continue to travel in a stream from the anode 96, between the pair of vertically disposed oscil-- loscope deflector plates 98 and I66, of which the plate 98 is shown grounded, and between the pair of horizontally disposed oscilloscope deflector plates I02 and I04, of which the plate I04 is shown grounded, to impinge finally on the fluorescent viewing screen I06 of the oscilloscope After each simultaneous horizontal sweep of both the oscilloscope 90, and the oscilloscopelike member 89 has been completed, a successively larger voltage will be applied to the horizontally disposed deflector plates I02, I04,.and I63, I05, respectively, by the vertical-sweep circuit. After at thefirst or top row.

successively disposed areas of the screen I06. of

the oscilloscope '90 will therefore correspond to the similarly disposed mosaic-antenna sections in the disc 9 of the member 89. Each spot-along a particular horizontal sweep, therefore, will become brightened on the screen I06 according to the amount of radio energy received by the corresponding pick-up element, and fed, by way of the amplifier 19, to the control electrode 92, of the cathode-ray oscilloscope 90.

A more sensitive video signal device might be any well-known bridge detector of, say, the Wheatstone construction. If the electrets are connected in a direct-current series circuit, then the bank of condenser electrets may serve as an extremely sensitive radio-detecting element of a Wheatstone bridge, in which they may be balanced against fixed impedance elements 2l-2, 214 and 216, as shown in Fig. 4. The short-circuitingor exploring of each successive electret by the electron stream, diagrammatically shown as shorting switches 205, 201, 209, in parallel with the electrets 204, 265, 208, would thus be markedly indicated in the amplifier 19 and fed to the control electrode 92 of the display oscilloscope 90.

Although the invention has been described in connection with mosaic-antennas arranged in rows and columns, it will be understood that this is not essential, for other arrangements are also possible. Antennas arranged along concentric circles covering the field, or a continuous spiral, will also serve, though the oscilloscope arrangement would, of course, be correspondingly modifled.

In the case of the concentric circles and the spiral, the antennas would be rendered effective in two-dimensional order, as in the case of the rows and columns before described. The antennas disposed along one of the circles, for example, would first be rendered effective, then those along the next circle, and so on.

Further modifications will occur to persons skilled in the art, and all such are considered to fall within the spirit and scope of the invention, as defined in the appended claims.

What is claimed is:

1. An electric system having, in combination, a plurality of permanently charged electrets, means for producing an electron stream for impinging on the plurality of electrets, and means for causing the electron stream to scan the plurality of electrets.

2. An electric system having, in combination, an oscilloscope-like member having a mosaic of permanently charged electrets for absorbing radio waves, means for producing an electron stream for impinging on the mosaic, and means for causing said stream to scan the mosaic.

3. An electric system having, in combination, radio-detecting means comprising a rectifying element sensitized with a permanent charge, and means for producing an electron stream for impinging on the radio-detecting means.

4. An electric system having, in combination,

radio-detecting means comprising an element 5. An "electric system having, in combinatiofi,

"a plurality of sets of permanently'charged electrets, the electrets of each set being connected together to :a common terminal, a load, and means for connecting the common terminals to the load.

minal, a load, means for connecting the common terminals to the load, and means for rendering the electrets o-f successive sets successively 015- f fective.

7. An electric system having, in combination, permanently charged electret means, and-means for producing an electron stream for impinging on the electret means.

8. In combination with a plurality of permanently charged electrets, a plurality of elements corresponding, respectively, to theplurality of electrets and capacitively coupled thereto.

9. A mosaic having an insulating support, and a plurality of permanently charged electrets supported by the support.

10. An electron tube having a screen, and a mosaic of permanently charged electrets supported by the screen. V

11. A plurality of radio-detecting elements each comprising a rectifying medium sensitized with a permanent charge, alternately disposed with a plurality of elements having no initial charge. 7

12. A plurality of radio-detecting elements each comprising a rectifying medium sensitized with an initial voltage and disposed alternately with a plurality of elements having no initialvoltage. V

13. In combination with amosaic of radio-receiving elements-each having radio-wave receiving antenna means tuned to the frequency of the radio waves and absorbing means responsive to the radio waves received by the antenna means for absorbing the radio waves received thereby, a mosaic having insulated elements corresponding, respectively, to the first-named elementsand c a-.- pacitively coupled thereto.

14. An electric system having, in combination, a mosaic of radio-receiving elements each having radio-wave receiving antenna means tuned to the frequency of the radio waves and absorbing means responsive to the radio waves received by 15.'In c,ombination with a mosaic of radio-re ceiving elementseach having radio-wave receiving antenna'means tuned to the frequency of the radio waves and rectifying means responsive to the radio waves received by the antenna means for absorbing andrectifying the received radiowaves, amosaic having elements corresponding, respectively, to the first-named elements and'ca'ipacitively 'coup'led thereto.

16. Anielectron tube having a screen, a mosaic of radio-receiving elements each having radiowave receiving antenna means tuned tothe frequency of'theradio waves and rectifying means responsive to the radio waves received by the antenna means, and a mosaic having elements corresponding, respectively, to the radio-receive ing elements and capacitively coupled thereto, one of the mosaics being carried by the screen.

17. An electric system having, in combination, a plurality of permanently charged elements each comprising a permanently polarized dielectric base, means for producing an electron stream for impinging on the plurality of elements, and means for causing the electron stream to scan the plurality of elements.

18. An electric system having, in combination, an oscilloscope-like member having a mosaic of permanently charged elements each comprising a permanently polarized dielectric base adapted to absorb radio waves, means for producing an electron stream for impinging on the mosaic, and means for causing said stream to scan the mosaic.

19. An electric system having, in combination, a plurality of sets of permanently charged elements each comprising a permanently polarized dielectric base, the elements of each set being connected together to a common terminal, a load, and means for connecting the common terminals to the load.

20. An electric system having, in combination, a plurality of sets of normally inefiective permanently charged elements each comprising a permanently polarized dielectric base, the elements of each set being connected together to a common terminal, a load, means for connecting the common terminals to the load, and means for rendering the elements of successive sets successively efiective.

21. An electric system having, in combination, permanently charged means comprising a permanently polarized dielectric base, and means for producing an electron stream for impinging on the permanently charged means.

22. In combination with a plurality of permanently charged elements each comprising a permanently polarized dielectric base, a plurality of elements corresponding, respectively, to the plurality of permanently charged elements and capacitively coupled thereto.

23. A mosaic having an insulating support, and a plurality of permanently charged elements each comprising a permanently polarized dielectric base supported by the support.

24. An electron tube having a screen, and a mosaic of permanently charged elements each comprising a permanently polarized dielectric base supported by the screen.

25. An electric system having, in combination, a plurality of permanently charged elements comprising a mixture of radio-wave absorbingand-rectifying material with a permanently polarized dielectric base, means for producing an electron stream for impinging on the plurality of elements, and means for causing the electron stream to scan the plurality of elements.

26. An electric system having, in combination, an oscilloscope-like member having a mosaic of permanently charged elements'each comprising a mixture of radio-wave absorbing-and-rectifying material with a permanently polarized dielectric base adapted to absorb and rectify radio waves, means for producing an electron stream for impinging on the mosaic, and means for causing said stream to scan the mosaic.

27. An electric system having, in combination, a plurality of sets of permanently charged elements each comprising a mixture of radio-wave absorbing-and-rectiiying material with a permanently polarized dielectric base, the elements of each set being connected together to a common terminal, a load, and means for connecting the common terminals to the load.

28. An electric system having, in combination, a plurality of sets of normally inefiective permanently charged elements each comprising a mixture of radio-Wave absorbing-and-rectifying material with a permanently polarized dielectric base, the elements of each set being connected together to a common terminal, a load, means for connecting the common terminals to the load, and means for rendering the elements of successive sets successively effective.

29. An electric system having, in combination,

permanently charged means comprising a. mixture of radio-Wave absorbing-and-rectifying material with a permanently polarized dielectric base, and means for producing an electron stream for impinging on the permanently charged means.

30. In combination with a plurality of permanently charged elements each comprising a mixture of radio-wave absorbing-and-rectifying material with a permanently polarized dielectric base, a plurality of elements corresponding, re-

spectively, to the plurality of permanently charged elements and capacitively coupled thereto.

31. A mosaic having an insulating support, and a plurality of permanently charged elements each comprising a mixture of radio-wave absorbing-and-rectifying material with a permanently polarized dielectric base supported by the support.

32. An electron tube having a screen, and a mosaic of permanently charged elements each comprising a mixture of radio-wave absorbingand-rectifying material with a permanently polarized dielectric base supported by the screen.

ROBERT H. RINES.

REFERENCES CITED The following references are of record in the file of this patent:

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